Liquid crystal molecules in a liquid crystal display has a characteristic that the liquid crystal molecule may not deflect in response to a change of electrical field to form different brightness, if the characteristic of the liquid crystal molecule has be destroyed because a pixel voltage applied on a pixel electrode always remains being unchanged. In order to avoid the above situation, the pixel voltage is generally divided into two polarities (a positive polarity and a negative polarity) in the prior art, wherein the voltage at the pixel electrode being higher than a voltage at a common electrode is referred as having the positive polarity, and the voltage at the pixel electrode being lower than the voltage at the common electrode is referred as having the negative polarity. A deflection direction of the liquid crystal molecule may be changed by changing the positive-negative polarity of the pixel voltage alternatively, in order to protect the liquid crystal molecule.
As illustrated in FIG. 1, which is an exemplary view illustrating a structure of a driving circuit of a liquid crystal display panel in the prior art, the driving circuit at least comprises a timing controller (TCON) and a data driver (Source Driver), wherein the timing controller may provide to the data driver a polarity inversion signal (POL) and digital video signals, and the data driver may generate analog video signal (that is, the pixel voltages described above) with opposite polarities in accordance with the change in levels of the polarity inversion signal and output the analog video signal to the pixel electrode in the liquid crystal display panel. That is to say, the positive polarity or the negative polarity of the level of the analog video signal applied to the pixel electrode is decided by the polarity inversion signal.
In the prior art, the polarity inversion signal provided to the data driver by the timing controller is unchanged, and the polarity inversion signal provided to the data driver by the timing controller cannot be changed according to different situations, which would brings many disadvantages.
For example, the existing liquid crystal display panel adopts a dot-inversion polarity driving manner to drive the data driver generally, but when such liquid crystal display panel displays images with all-white picture or all-black picture required as testing, a switching frequency of an analog video signal output subsequently is quite frequent since change of levels in the polarity inversion signal corresponding to the dot-inversion polarity driving manner is performed per sub-pixel or per pixel, which may increase a power consumption of the data driver.